The .30 Walker is an intermediate cartridge developed by Mark Walker of Houston, Texas. This cartridge is an improved version of the PPC

6 mm PPC

The 6 mm PPC , or 6 PPC as it is more often called, is a centerfire rifle cartridge used almost exclusively for benchrest shooting. At distances out to 300 yards, it is one of the most accurate cartridges available...

 cartridge family. The .30 Walker was designed for 100-300 yard bench rest and f-class shooting using 112-118 grain flat based bullets in slow twist rate barrels.

The .30 Walker is made by using Lapua 6.5 mm Grendel brass and increasing the caliber to .308 and turning the neck diameter to .330".